Description of problem:
Trigger v3.11 installation on rhel. Installation failed at TASK [openshift_ca : Install the base package for admin tooling] ***************
Thursday 16 August 2018  07:06:32 +0800 (0:00:00.088)       0:06:37.972 ******* 
...
FAILED - RETRYING: Install the base package for admin tooling (1 retries left).
fatal: [x -> x]: FAILED! => {"attempts": 3, "changed": false, "msg": "No package matching 'atomic-openshift-3.11*' found available, installed or updated", "rc": 126, "results": ["No package matching 'atomic-openshift-3.11*' found available, installed or updated"]}
==================
Checked installation log, found that before task[openshift_ca : Install the base package for admin tooling], openshift excluder was enabled(exclude), so atomic-openshift-3.11* package should not be searched in yum list.

Dig more, compared with earlier 3.11 installation log, atomic-openshift-3.11* package was installed as a dependency of atomic-openshift-node-3.11 in previous task [openshift_node : Install node, clients, and conntrack packages], so when it came to task [openshift_ca : Install the base package for admin tooling], no action needed.

But in v3.11.0-0.16.0, atomic-openshift-3.11* is not treated as a dependency of atomic-openshift-node-3.11, so atomic-openshift-3.11* package needed to be installed in post task. But openshift excluder was enabled before that. 

To be conclusion, if installer will drop the dependency between atomic-openshift-3.11* and atomic-openshift-node-3.11*, then need unexclude openshift-excluder before install atomic-openshift-3.11. Or else, need restore the dependency.

[root@qe-smoke311-merrn-1 ~]# yum install atomic-openshift-node-3.11*
...
Dependencies Resolved

========================================================================================================================================
 Package                               Arch              Version                                       Repository                  Size
========================================================================================================================================
Installing:
 atomic-openshift-node                 x86_64            3.11.0-0.16.0.git.0.6bcbde8.el7               ose-smoke-devel            7.1 M
Installing for dependencies:
 atomic-openshift-hyperkube            x86_64            3.11.0-0.16.0.git.0.6bcbde8.el7               ose-smoke-devel             35 M

Transaction Summary
========================================================================================================================================
Install  1 Package (+1 Dependent package)


Version-Release number of the following components:
openshift-ansible-3.11.0-0.16.0.git.0.e82689aNone.noarch.rpm

How reproducible:
always

Steps to Reproduce:
1. Trigger installation on rhel
2.
3.

Actual results:
Installation failed.

Expected results:
Installation succeed.

Additional info:
workaround should be set "openshift_enable_openshift_excluder=false" in hosts file.